Preventing surgical site infections after bariatric surgery: value of perioperative antibiotic regimens

Abdominal Drains After Laparoscopic Sleeve Gastrectomy: Should They Be Used?

Purpose

Laparoscopic sleeve gastrectomy (LSG) is one of the most common surgical procedures worldwide for the treatment of morbid obesity. Blake-type drains are widely used in this procedure despite the lack of clear evidence regarding their benefits in the diagnosis and treatment of common postoperative complications such as gastric suture line leak (GSLL) and postoperative bleeding (PB).

Materials and Methods

A retrospective descriptive study with prospective case registry was conducted, analyzing all patients who underwent LSG between January 2012 and December 2022 at a high-volume center. Our primary outcome was to evaluate the role of drains for diagnosis and treatment of GSLL and PB in LSG. Our secondary outcome was to determine drain related surgical site infection (DRSSI) rate.

Results

A total of 335 LSG were performed in the studied period. In all patients one abdominal drain was placed during surgery. Six GSLL (1.79%) and 5 PB (1.49%) were recorded. Drain placement did not prove to ensure early diagnosis or conservative management of GSLL or PB after LSG. Furthermore, an incidence of DRSSI of 4.1% (14 patients) was found.

Conclusion

In our study, no clear diagnostic or therapeutic benefits of the systematic use of drains for GSLL or PB in LSG was found; but drain use did show a considerable rate of DRSSI, which must be taken into consideration prior to considering drain systematic use. While no randomized prospective trials have been performed, the retrospective data does not support drain systematic use.

Safety of limb lengthening after Roux-en-Y gastric bypass: an analysis of the MBSAQIP database

BACKGROUND

Roux-en-Y gastric bypass (RYGB) effectively treats severe obesity, but some patients may require revisional surgery like limb lengthening (LL) for postoperative weight gain.

OBJECTIVES

This study aims to compare 30-day serious complications and mortality rates between LL and primary RYGB, given limited safety data on LL.

METHODS

Patients who underwent LL and RYGB were identified from the 2020 and 2021 MBSAQIP databases, the only years in which LL data were available. Baseline characteristics and 30-day rates of serious complications and mortality were analyzed.

RESULTS

A total of 86,990 patients underwent RYGB and 455 underwent LL. Patients undergoing RYGB were younger (44.4 versus 49.8 yr, P < .001), had a higher body mass index (BMI) (45.5 versus 41.8 kg/m2, P < .001) and higher rates of comorbidities including diabetes (30.0 versus 13.6%, P < .001). RYGB and LL had similar operative duration (125.3 versus 123.2 min, P = .5). There were no statistical differences between cohorts for length of stay (LOS) (1.6 RYGB versus 1.6 LL d, P = .6). After LL, there were higher 30-day rates of reoperation (3.3 versus 1.9%, P = .03) and deep surgical site infections (1.3 versus .5%, P = .03) compared to RYGB. There were no differences in overall serious complications (5.1 LL versus 5.0% RYGB, P = 1.0) and mortality (.2 LL versus .1% RYGB, P = .5). Multivariable logistic regression adjustment found that previous venous thromboembolism was associated with serious complications after LL.

CONCLUSIONS

When compared to primary RYGB, LL has a favorable safety profile with similar 30-day rates of serious complications and mortality.

From basic research to clinical practice: The impact of laminar airflow filters on surgical site infection in vascular surgery

BACKGROUND

Laminar airflow filters have been suggested as a potential preventive factor for surgical site infections, given their ability to reduce the airborne microbiological load. However, their role is still unclear, and evidence regarding vascular surgery patients is scarce. Our aim was to assess the impact of laminar-airflow filters on surgical site infections.

METHODS

This single-centre retrospective cohort study was conducted with vascular surgery patients who underwent arterial vascular intervention through a groin incision between July 2018 and July 2019 (turbulent airflow cohort) and July 2020 and July 2021 (laminar airflow cohort). Data were prospectively collected from electronic medical files. We estimated the cumulative incidence of surgical site infections and its 95% confident interval (95%CI). A propensity score matching analysis was performed.

RESULTS

We included 200 patients, 78 in the turbulent airflow cohort and 122 in the laminar airflow cohort. The cumulative incidence was 15.4% (12/78; 95%CI: 9.0-25.0%) in the turbulent-airflow cohort and 14.8% (18/122; 95%CI: 9.5 -22.1%) in the laminar-airflow cohort (p-value: 1.00). The propensity score matching yielded a cumulative incidence of surgical site infection of 13.9% (10/72) with turbulent airflow and 12.5% (9/72) with laminar airflow (p-value: 1.00). Risk factors associated with infection were chronic kidney disease (OR 2.70; 95%CI: 1.14-6.21) and a greater body mass index (OR 1.47; 95%CI: 1.01-2.14).

CONCLUSION

Laminar airflow filters were associated with a non-significant reduction of surgical site infections. Further research is needed to determine its usefulness and cost-effectiveness. Surgical site infection incidence was associated with chronic kidney disease and a greater body mass index. Hence, efforts should be made to optimize the body mass index before surgery and prevent chronic kidney disease in patients with known arterial disease.

Obesity at term: What to consider? How to deliver?

Obesity presents significant challenges during pregnancy, increasing the risk of complications and adverse outcomes for both mother and baby. With the rising prevalence of obesity among pregnant women, questions arise regarding optimal management, including timing of delivery and choice of delivery mode. Labour induction in obese women may require a combination of mechanical and pharmacological methods due to increased risk of failed induction. Caesarean section in obese women presents unique challenges, requiring comprehensive perioperative planning and specialized care to optimize outcomes. However, specific guidelines tailored to obese patients undergoing caesarean sections are lacking. Postpartum care should include vigilant monitoring for complications. Addressing obesity in pregnancy necessitates a multidisciplinary approach and specialized care to ensure the best outcomes.

Perioperative Antibiotic Prophylaxis

BACKGROUND

Postoperative surgical site infections (SSI) account for almost 25% of all nosocomial infections in Germany and are a source of increased morbidity and mortality.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed and on national and international guidelines.

RESULTS

The individual risk factors for SSI must be assessed before any surgical procedure. A body-mass index above 30 kg/m2 is associated with an unadjusted risk ratio of 1.35 [1.28; 1.41] for SSI, which rises to 3.29 [2.99; 3.62] if the patient is also immunosuppressed. The risk of SSI is also significantly higher with certain types of procedure. Perioperative antibiotic prophylaxis (PAP) is clearly indicated for operations that carry a high risk of SSI (e.g., colorectal surgery) and for those that involve the implantation of alloplastic material (e.g., hip endoprostheses). PAP can usually be administered with basic antibiotics such as cefazoline. The basic principles of PAP are that it should be given by the anesthesia team in the interval from 60 minutes preoperatively up to shortly before the incision, and that its administration should only be for a short period of time, usually as a single shot. Continuing PAP onward into the postoperative period leads to increased toxicity, bacterial superinfections, and antibiotic resistance.

CONCLUSION

The evidence shows that perioperative antibiotic prophylaxis is a component of a bundle of measures that can help prevent SSI. Strict indications and adherence to the basic principles of PAP are essential for therapeutic success.

Determination of Antimicrobial Resistance and the Impact of Imipenem + Cilastatin Synergy with Tetracycline in Pseudomonas aeruginosa Isolates from Sepsis

Pseudomonas aeruginosa is among the most ubiquitous bacteria in the natural world, exhibiting metabolic and physiological versatility, which makes it highly adaptable. Imipenem + cilastatin and tetracycline are antibiotic combinations commonly used to treat infections caused by P. aeruginosa, including serious infections such as sepsis. In the context of bacterial infections, biofilm, formed by bacterial cells surrounded by extracellular substances forming a matrix, plays a pivotal role in the resistance of P. aeruginosa to antibiotics. This study aimed to characterize a representative panel of P. aeruginosa isolates from septicemias, assessing their susceptibility to various antibiotics, specifically, imipenem + cilastatin and tetracycline, and the impact of these treatments on biofilm formation. Results from antibiotic susceptibility tests revealed sensitivity in most isolates to six antibiotics, with four showing near or equal to 100% sensitivity. However, resistance was observed in some antibiotics, albeit at minimal levels. Notably, tetracycline showed a 100% resistance phenotype, while imipenem + cilastatin predominantly displayed an intermediate phenotype (85.72%), with some resistance (38.1%). Microdilution susceptibility testing identified effective combinations against different isolates. Regarding biofilm formation, P. aeruginosa demonstrated the ability to produce biofilms. The staining of microtiter plates confirmed that specific concentrations of imipenem + cilastatin and tetracycline could inhibit biofilm production. A significant proportion of isolates exhibited resistance to aminoglycoside antibiotics because of the presence of modifying genes (aac(3)-II and aac(3)-III), reducing their effectiveness. This study also explored various resistance genes, unveiling diverse resistance mechanisms among P. aeruginosa isolates. Several virulence genes were detected, including the las quorum-sensing system genes (lasI and lasR) in a significant proportion of isolates, contributing to virulence factor activation. However, genes related to the type IV pili (T4P) system (pilB and pilA) were found in limited isolates. In conclusion, this comprehensive study sheds light on the intricate dynamics of P. aeruginosa, a remarkably adaptable bacterium with a widespread presence in the natural world. Our findings provide valuable insights into the ongoing battle against P. aeruginosa infections, highlighting the need for tailored antibiotic therapies and innovative approaches to combat biofilm-related resistance.

Are iodophor-impregnated drapes associated with lower intraoperative contamination compared to no adhesive drape?: A protocol for systematic review and meta analysis

BACKGROUND

Surgical site infection (SSI) is one of the most frightening complications after surgery. Adhesive drapes (AD) are widely used as an infection prevention tool. They can be non-impregnated or iodophor-impregnated, although non-impregnated are less used as they might be related to higher number of infections. One of the most common ways to study their efficacy is by analyzing the intraoperative contamination, which is a useful primary endpoint as it does not need follow-up and it has been strongly associated with infections. Therefore, we believe a systematic review (SR) and meta-analysis is needed to determine which is the literature available about this topic and to explore their results.

METHODS

All randomized controlled trials (RCT) published since 1984 through to January 15, 2023 will be included. Non-human and experimental studies will be excluded. We will only include studies written in English. We will conduct searches in the following electronic databases: MEDLINE (via PubMed), SCOPUS and Web Of Science. The protocol of the SR was registered in PROSPERO under the number CRD42023391651 and was written according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocol guidelines.

DISCUSSION

The evidence regarding the benefits of using iodophor-impregnated adhesive drapes (IIAD) is scarce. Therefore, this SR and meta-analysis is required to determine if they are related with a lower intraoperative contamination incidence, compared to no AD.

A physiologically based pharmacokinetic model of cefepime to predict its pharmacokinetics in healthy, pediatric and disease populations

The physiologically based pharmacokinetic modeling (PBPK) approach can predict drug pharmacokinetics (PK) by combining changes in blood flow and pathophysiological alterations for developing drug-disease models. Cefepime hydrochloride is a parenteral cephalosporin that is used to treat pneumonia, sepsis, and febrile neutropenia, among other things. The current study sought to identify the factors that impact cefepime pharmacokinetics (PK) following dosing in healthy, diseased (CKD and obese), and pediatric populations. For model construction and simulation, the modeling tool PK-SIM was utilized. Estimating cefepime PK following intravenous (IV) application in healthy subjects served as the primary step in the model-building procedure. The prediction of cefepime PK in chronic kidney disease (CKD) and obese populations were performed after the integration of the relevant pathophysiological changes. Visual predictive checks and a comparison of the observed and predicted values of the PK parameters were used to verify the developed model. The results of the PK parameters were consistent with the reported clinical data in healthy subjects. The developed PBPK model successfully predicted cefepime PK as observed from the ratio of the observed and predicted PK parameters as they were within a two-fold error range.

A Multidisciplinary Approach to Improvements in Perioperative Antibiotic Prophylaxis at a Military Treatment Facility

INTRODUCTION

Surgical site infections complicate 2%-5% of surgeries. According to the Centers for Disease Control and Prevention, half of all surgical site infections are preventable. Adherence to published recommendations regarding perioperative antibiotic administration decreases the incidence of surgical site infections. Members of the Department of Anesthesia noticed casual observations of inaccurate prescribing of antibiotics at our institution, Brooke Army Medical Center, and approached the Antimicrobial Stewardship Program to collaborate on this issue.

MATERIALS AND METHODS

A team of anesthesiologists, clinical pharmacists, and infectious disease specialists collaborated with the Department of Surgery to improve this effort as part of a multiyear project from 2018 to 2021. We first assessed adherence to recommended perioperative antibiotic use to establish a baseline and next, noticing gaps, created a project with the goal to improve compliance to >90% across surveyed measures. Our key interventions included educational initiatives, creation of facility-specific guidelines, peer benchmarking, updating order sets, interdisciplinary collaboration, creation of intraoperative reminders and visual aids, and tailored presentations to selected services.

RESULTS

Of 292 charts (2.3% of cases from January to October 2018) reviewed pre-intervention, compliance rates were 84% for antibiotic choice, 92% for dose, 65% for redosing, and 71% for postoperative administration. Of doses, 100% were timed correctly, and thus, this variable was not targeted. Post-intervention, our review of 387 charts (10% of cases from May to November 2020) showed no change in correct antibiotic choice (84%) and statistical improvement to 96% for correct dose, 95% for correct redosing, and 85% for correct postoperative administration (P < .05 for all).

CONCLUSIONS

Our multidisciplinary approach of collaboration with multiple departments, creating guidelines and providing feedback, improved compliance with perioperative antibiotic administration recommendations.

Role of ultrasound in the treatment of pediatric infectious diseases: case series and narrative review

BACKGROUND

Infectious diseases are common in pediatric patients. In these patients, ultrasound is a useful imaging modality that involves no irradiation or sedation and can be performed repeatedly at the patient's bedside. The purpose of this review was to show pediatric cases with infectious disease that used ultrasound to decide the methods of treatment.

DATA SOURCES

Literature review was performed using Pubmed as the medical database source. No year-of-publication restriction was placed. The mesh terms used were: "ultrasound", "sonography", "infectious disease", "treatment", "antibiotics", "surgical intervention", "pediatric", "children", "deep neck abscess", "pyothorax", "empyema", "pneumonia", "urinary tract infection", "intra-abdominal abscess", "soft tissue infection", "septic arthritis", "osteomyelitis", and "surgical site infection".

RESULTS

We presented pediatric case series with infectious diseases, including deep neck abscess, pyothorax and empyema, pneumonia, urinary tract infection, intra-abdominal abscess, soft tissue infection, septic arthritis and osteomyelitis, and surgical-site infection. Ultrasound was useful for evaluating the extent and location of inflammation and abscess and for decision-making concerning surgical intervention.

CONCLUSION

Knowledge of these sonographic findings is important for sonographers during examinations and for physicians when determining the treatment plan and period of antibiotic therapy for infected lesions.

Incidence, Burden, and Predictors of 11-Month Readmission in Patients Undergoing Bariatric Surgery

BACKGROUND

Bariatric surgery (BSx) is one of the most common surgical procedures performed in the USA. Nonetheless, data regarding 11-month period after BSx remain limited.

METHODS

A retrospective cohort study using the 2016 National Readmission Database. Adult patients admitted for BSx in January were included. The follow-up period was 11 months (February-December). The primary outcome was all-cause 11-month readmission. Secondary outcomes were index admission (IA) and readmission in-hospital mortality rate and healthcare resource use associated with readmission. Multivariate regression was performed to identify independent risk factors for readmission.

RESULTS

A total of 13,278 IA were included. The 11-month readmission rate was 11.1%. The mortality rate of readmission was 1.4% and 0.1% for IA (P < 0.01). The most common cause of readmission was hematemesis. Independent predictors were Charlson comorbidity index (CCI) score ≥ 3 (adjusted hazard ratio [aHR] 1.34; P = 0.05), increasing length of stay (aHR 1.01; P < 0.01), transfer to rehabilitation facilities (aHR 5.02; P < 0.01), undergoing laparoscopic Roux-en-Y gastric bypass (aHR 1.71; P = 0.02), adjustable gastric band (aHR 14.09; P < 0.01), alcohol use disorder (2.10; P = 0.01), and cannabis use disorder (aHR 3.37; P = 0.01). Private insurance as primary payer (aHR 0.65; P < 0.01) and BMI 45-49 kg/m² (aHR 0.72; P < 0.01) were associated with less odds of readmission. The cumulative total hospitalization charges of readmission were $69.9 million.

CONCLUSIONS

The 11-month readmission rate after BSx is 11.1%. Targeting modifiable predictors of readmission may help reduce the burden of readmissions on our healthcare system.

Groin surgical site infection incidence in vascular surgery with intradermal suture versus metallic stapling skin closure: A study protocol for a pragmatic open-label parallel-group randomized clinical trial (VASC-INF trial)

BACKGROUND

Surgical site infection is 1 of the most frightening complications in vascular surgery due to its high morbimortality. The use of intradermal sutures for skin closure might be associated with a reduction in infections incidence. However, the data available in the literature is scarce and primarily built on low-evidence studies. To our knowledge, no multicenter clinical trial has been published to assess if the intradermal suture is associated with a lower surgical site infection incidence than metallic staples in patients who will undergo revascularization surgery requiring a femoral approach.

METHODS

VASC-INF is a pragmatic, multicenter, multistate (Spain, Italy, and Greece), randomized, open-label, clinical trial assessing the surgical site infection incidence in patients undergoing revascularization surgery requiring a femoral approach. Patients will be randomized on a 1:1 ratio to intradermal suture closure (experimental group) or to metallic staples closure (control group).The primary outcome is the number (percentage) of patients with surgical site infection (superficial and/or deep) associated with a femoral approach up to 28 (±2) days after surgery. Among the secondary outcomes are the number (percentage) of patients with other surgical wound complications; the number (percentage) of patients with surgical site infections who develop sepsis; type of antibiotic therapy used; type of microorganisms' species isolated and to describe the surgical site infection risk factors.

DISCUSSION

Intradermal suture closure may be beneficial in patients undergoing revascularization surgery requiring a femoral approach. Our working hypothesis is that intradermal suture closure reduces the incidence of surgical site infection respect to metallic staples closure.

Towards interpretable, medically grounded, EMR-based risk prediction models

Machine-learning based risk prediction models have the potential to improve patient outcomes by assessing risk more accurately than clinicians. Significant additional value lies in these models providing feedback about the factors that amplify an individual patient's risk. Identification of risk factors enables more informed decisions on interventions to mitigate or ameliorate modifiable factors. For these reasons, risk prediction models must be explainable and grounded on medical knowledge. Current machine learning-based risk prediction models are frequently 'black-box' models whose inner workings cannot be understood easily, making it difficult to define risk drivers. Since machine learning models follow patterns in the data rather than looking for medically relevant relationships, possible risk factors identified by these models do not necessarily translate into actionable insights for clinicians. Here, we use the example of risk assessment for postoperative complications to demonstrate how explainable and medically grounded risk prediction models can be developed. Pre- and postoperative risk prediction models are trained based on clinically relevant inputs extracted from electronic medical record data. We show that these models have similar predictive performance as models that incorporate a wider range of inputs and explain the models' decision-making process by visualizing how different model inputs and their values affect the models' predictions.

Application of a Physiologically Based Pharmacokinetic Model to Predict Cefazolin and Cefuroxime Disposition in Obese Pregnant Women Undergoing Caesarean Section

Intravenous (IV) cefuroxime and cefazolin are used prophylactically in caesarean sections (CS). Currently, there are concerns regarding sub-optimal dosing in obese pregnant women compared to lean pregnant women prior to CS. The current study used a physiologically based pharmacokinetic (PBPK) approach to predict cefazolin and cefuroxime pharmacokinetics in obese pregnant women at the time of CS as well as the duration that these drug concentrations remain above a target concentration (2, 4 or 8 µg/mL or µg/g) in plasma or adipose tissue. Cefazolin and cefuroxime PBPK models were first built using clinical data in lean and in obese non–pregnant populations. Models were then used to predict cefazolin and cefuroxime pharmacokinetics data in lean and obese pregnant populations. Both cefazolin and cefuroxime models sufficiently described their total and free levels in the plasma and in the adipose interstitial fluid (ISF) in non–pregnant and pregnant populations. The obese pregnant cefazolin model predicted adipose exposure adequately at different reference time points and indicated that an IV dose of 2000 mg can maintain unbound plasma and adipose ISF concentration above 8 µg/mL for 3.5 h post dose. Predictions indicated that an IV 1500 mg cefuroxime dose can achieve unbound plasma and unbound ISF cefuroxime concentration of ≥8 µg/mL up to 2 h post dose in obese pregnant women. Re-dosing should be considered if CS was not completed within 2 h post cefuroxime administration for both lean or obese pregnant if cefuroxime concentrations of ≥8 µg/mL is required. A clinical study to measure cefuroxime adipose concentration in pregnant and obese pregnant women is warranted.

Combinatorial Therapeutic Strategy of Biogenics Derived from Lactobacillus fermentum PUM and Zingerone Against Pseudomonas aeruginosa PAO1-Induced Surgical Site Infection: an Experimental Study

Pseudomonas aeruginosa, a WHO-prioritized multidrug-resistant Gram-negative bacteria, is one of the frequently implicated pathogen in surgical site infection (SSI) due to its virulence phenotypes and biofilm-forming ability. In the present study, cell-free supernatant (CFS) and biogenics (organic acids and precipitated protein fraction) of indigenous potential probiotic, Lactobacillus fermentum PUM both alone and in combination with zingerone were found to inhibit pyocyanin, pyochelin, protease, elastase, the virulence factors, and motility of P. aeruginosa PAO1. Furthermore, scanning electron microscopy indicated that biofilm formation was attenuated maximally by CFS of L. fermentum combined with zingerone. In vivo study revealed reduced P. aeruginosa burden, suppuration at surgical site vis-a-vis reduced levels of oxidants, pro-inflammatory cytokines, ameliorated anti-oxidants, and healed infected surgical site compared with counter controls. In totality, combination of L. fermentum PUM-derived biogenics and zingerone could be employed to treat P. aeruginosa-induced SSI that needs to be correlated clinically.

Surgical Antibiotic Prophylaxis in an Era of Antibiotic Resistance: Common Resistant Bacteria and Wider Considerations for Practice

The increasing incidence of antimicrobial resistance (AMR) presents a global crisis to healthcare, with longstanding antimicrobial agents becoming less effective at treating and preventing infection. In the surgical setting, antibiotic prophylaxis has long been established as routine standard of care to prevent surgical site infection (SSI), which remains one of the most common hospital-acquired infections. The growing incidence of AMR increases the risk of SSI complicated with resistant bacteria, resulting in poorer surgical outcomes (prolonged hospitalisation, extended durations of antibiotic therapy, higher rates of surgical revision and mortality). Despite these increasing challenges, more data are required on approaches at the institutional and patient level to optimise surgical antibiotic prophylaxis in the era of antibiotic resistance (AR). This review provides an overview of the common resistant bacteria encountered in the surgical setting and covers wider considerations for practice to optimise surgical antibiotic prophylaxis in the perioperative setting.

The Effect of Tissue Adhesive on Surgical Site Infection Following Elective Bariatric Surgery: a Retrospective Cohort Study

PURPOSE

The reported incidence of surgical site infection (SSI) following bariatric surgery ranges from 1.4 to 30%. The use of skin staples and tissue adhesive was shown to be superior to sutures in reducing SSI in a variety of surgical disciplines; however, this area is under-investigated in elective bariatric surgery. The aim of this study was to examine the effect of tissue adhesive for skin closure on SSI in patients undergoing bariatric surgery.

METHODS

A retrospective analysis was performed to determine the incidence of SSI in patients who underwent elective laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG). Tissue adhesive was selectively used for skin closure during the study period. Patient characteristics, operative data, and 30-day postoperative outcomes were collected from patient charts and the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database.

RESULTS

A total of 1,579 patients were included in the study. Tissue adhesive was used in 31.2% of all operations (n = 494). The rate of incisional SSI in our study was 2.2% (n = 35). The use of tissue adhesive was more common in patients who developed incisional SSI compared with those without incisional SSI (54.3 vs. 30.8%, p = 0.003). On multivariate analysis, the use of tissue adhesive remained an independent predictor for the development of incisional SSI (OR 2.77, p = 0.007).

CONCLUSION

The use of tissue adhesive was an independent predictor for incisional SSI following elective bariatric surgery. This is the first study to report the effects of tissue adhesive in this patient population.

Antibiotic Prophylaxis in Bariatric Surgical Procedures: Is There an Ideal Antimicrobial Agent?

When patients with significant comorbid risk factors undergo surgical procedures, they are at high risk for development of post-operative infectious complications, including surgical site infection (SSI). Obese patients characteristically fit within this risk category, and thus it is of paramount importance to establish evidence-based strategies to mitigate these infectious complications. The use of an antimicrobial prophylactic regimen is a well-established practice and is based on the principle of the "right drug, at the right time, in the right place." The subject of this article is to review the current evidence-based data on antimicrobial prophylaxis in obese patients undergoing bariatric surgical procedures.

Refractory Unforeseen Anaphylaxis Case in a Rural OR Unit

A 35-year-old female patient with no previously documented allergies who was admitted for elective gynaecological surgery, developed rapid onset, severe anaphylaxis, with dyspnea and cardiovascular collapse, in the operating theatre after receiving routine IV cefazolin prior to induction of anesthesia. She failed to improve with two doses of intramuscular epinephrine followed by two boluses of intravenous epinephrine, but responded to an epinephrine infusion. She was assessed by Internal Medicine and discharged home the following day. This event demonstrates the speed, severity, and profound hypotension in an allergic reaction from intravenous medication, challenges in managing anaphylaxis, and importance of prompt administration of epinephrine via IM route, followed by IV if necessary, in the OR. The case highlighted the inability to ascertain the causative agent through typical allergy testing.

Surgical Antimicrobial Prophylaxis and Incidence of Surgical Site Infections at Ethiopian Tertiary-Care Teaching Hospital

BACKGROUND

Surgical site infections (SSIs) are infections that develop within 30 days after an operation or surveillance of surgical wound infection implementation within 90 days after surgery when an implant is placed. The objective of this study was to assess preoperative and postoperative antimicrobial use in St. Paul's Hospital Millennium Medical College (SPHMMC), Addis Ababa, Ethiopia.

METHODS

A hospital-based cross-sectional study was undertaken in surgery wards of SPHMMC for 4 months by reviewing 413 patients' charts. All patients 13 years and older who were admitted and underwent different types of surgical procedures were included in the study. Epi info 7 was used for data entry, and then data were exported to Statistical Package for Social Sciences (SPSS) version 20.0 software for analysis. Descriptive analyses were computed and rate of SSI was calculated in this study. Moreover, bivariate analysis was done to examine the relationship between the outcome variable and predictor variables with a value of P < .2 retained for subsequent multivariate analyses using multiple logistic regressions. P value of <.05 was considered as statistically significant.

RESULTS

Out of 413 patients, 152 (36.8%) were operated for general surgery, and the remaining were for other types of surgeries. Most of the patients, 196 (79.7%), were managed by a single surgical antibiotic agent, followed by 2 agents (20.3%) for surgical prophylaxis indication. Surgical site infections occurred in 46 (11.1%) patients before discharge from the hospital. In those patients who need treatment for SSIs, almost half of them (49.5%) received combination therapy of ceftriaxone and metronidazole. Emergency surgical cases were 2.647 times more likely to develop SSIs than the elective surgical cases (adjusted odds ratio [AOR] = 2.647; 95% confidence interval [CI] = 1.406-4.983; P = .003). Patients who did not receive antibiotic prophylaxis were 2.572 times more likely to develop SSIs compared to those who received antibiotic prophylaxis (AOR = 2.572; 95% CI = 1.02-6.485; P = .045). Clean-contaminated and contaminated types of wound were a protective factor against SSI in our study.

CONCLUSIONS

This study indicated that most of the patients (72.1%) received surgical antimicrobial prophylaxis. The overall incidence rate of SSIs was 11.1% in the studied hospital. Ceftriaxone was the most commonly used drug. Being not receiving prophylaxis, wound class, and surgery types were significantly associated with the development of SSI.

Comparison of Early Morbidity and Mortality Between Sleeve Gastrectomy and Gastric Bypass in High-Risk Patients for Liver Disease: Analysis of American College of Surgeons National Surgical Quality Improvement Program

INTRODUCTION

Chronic liver disease is prevalent in obese patients presenting for bariatric surgery and is associated with increased postoperative morbidity and mortality (M&M). There are no comparative studies on the safety of different types of bariatric operations in this subset of patients.

OBJECTIVE

The aim of this study is to compare the 30-day postoperative M&M between laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-Y-gastric bypass (LRYGB) in the subset of patients with a model of end-stage liver disease (MELD) score ≥ 8.

METHODS

Data for LSG and LRYGB were extracted from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from years 2012 and 2013. MELD score was calculated using serum creatinine, bilirubin, INR, and sodium. Postoperative M&M were assessed in patients with a score ≥ 8 and compared for the type of operation. This was followed by analysis for MELD subcategories. Multiple logistic regression was performed to adjust for confounders.

RESULTS

Out of 34,169, 9.8% of cases had MELD ≥ 8 and were included. Primary endpoint, 30-day M&M, was significantly lower post-LSG (9.5%) compared to LRYGB (14.7%); [AOR = 0.66(0.53, 0.83)]. Superficial wound infection, prolonged hospital stay, and unplanned readmission were more common in LRYGB. M&M post-LRYGB (30.6%) was significantly higher than LSG (15.7%) among MELD15-19 subgroup analysis.

CONCLUSION

LRYGB is associated with a higher postoperative risk than LSG in patients with MELD ≥ 8. The difference in postoperative complications between procedures was magnified with higher MELD. This suggests that LSG might be a safer option in morbidly obese patients with higher MELD scores, especially above 15.

Prophylactic cefazolin concentrations in morbidly obese patients undergoing sleeve gastrectomy: do we achieve targets?

Morbid obesity is known to increase the risk of surgical site infections. Optimal concentrations of prophylactic antibacterial drugs are required. Using Monte Carlo simulations, the aim of this work was to build a population pharmacokinetics model for a morbidly obese population to assess a 4000-mg dose of cefazolin recommended by the guidelines and to propose new administration schemes. One hundred and seventeen morbidly obese patients (mean body mass index, 46.95 kg/m²) received 4000 mg of cefazolin intravenously before sleeve gastrectomy. Using population pharmacokinetics modelling and Monte Carlo simulations, probabilities of target attainment (PTAs) (subcutaneous tissue concentration of cefazolin above the minimum inhibitory concentration (MIC) throughout the surgical procedure was targeted) were determined. For Staphylococcus spp. and Streptococcus spp., which are the most frequent species isolated from post-surgical infections in bariatric surgery (MIC usually ≤2 mg/L), PTA remains greater than 0.9 until 2 h after administration of 4000 mg of cefazolin. For MIC up to 4 mg/L, efficient prophylaxis was checked until 1 h after the initial administration. A 3000-mg regimen followed by a continuous infusion (1000 mg/h) achieves these two targets until 4 h after the loading dose. A 2000-mg and a 3000-mg regimen do not achieve sufficient concentrations. According to the duration of surgery and MIC values, an initial administration of 4000 mg should be sufficient, but for extended surgeries continuous infusion can be considered.

Simple, Safe, and Cost-Effective Technique for Resected Stomach Extraction in Laparoscopic Sleeve Gastrectomy

Background. Laparoscopic sleeve gastrectomy (LSG) has become a popular operation during the recent years. This procedure requires resection of 80–90% of the stomach. Extraction of gastric specimen is known to be a challenging and costly stage of the operation. In this paper, we report results of a simple and cost-effective specimen extraction technique which was applied to 137 consecutive LSG patients. Methods. Between October 2013 and October 2015, 137 laparoscopic sleeve gastrectomy surgeries were performed at Dokuz Eylul University General Surgery Department, Upper Gastrointestinal Surgery Unit. All specimens were extracted through a 15 mm trocar site without using any special device. Results. We noticed one superficial incisional surgical site infection and treated this patient with oral antibiotics. No cases of trocar site hernia were observed. Conclusion. Different techniques have been described for specimen extraction. This simple technique allows extraction of specimen safely in a short time and does not require any special device.

Acute Abdominal Pain in the Bariatric Surgery Patient

Obesity is present in epidemic proportions in the United States, and bariatric surgery has become more common. Thus, emergency physicians will undoubtedly encounter many patients who have undergone one of these procedures. Knowledge of the anatomic changes specific to these procedures aids the clinician in understanding potential complications and devising an organized differential diagnosis. This article reviews common bariatric surgery procedures, their complications, and the approach to acute abdominal pain in these patients.

Impact of obesity on the risk of wound infection following surgery: results from a nationwide prospective multicentre cohort study in England

We sought to assess the impact of body mass index on the risk of surgical site infection in a prospective cohort study of 206 National Health Service (NHS) hospitals in England between 2007 and 2011. Body mass index was available for 159,720 of 350,089 operations among patients undergoing abdominal hysterectomy, coronary artery bypass graft, hip replacement, knee replacement, or large-bowel surgery. Among these patients, the risk of surgical site infection ranged from 0.65% for knee replacement to 11.04% for large-bowel surgery. Overall, 127,512 (79.8%) patients were overweight or obese (body mass index of ≥25 kg/m(2)). Obesity was associated with a 1.1-fold to 4.4-fold increase in the adjusted odds of developing surgical site infection as compared with normal weight, depending on the type of surgery. The population-attributable fraction (PAF) for body mass index was greatest in overweight (body mass index of 25.0-29.9 kg/m(2)) patients undergoing coronary artery bypass graft, accounting for 15% of their overall risk of surgical site infection (PAF 0.15; 95% CI 0.09-0.22). Being overweight or obese substantially increased the likelihood of patients developing surgical site infection. Given the increasingly high proportion of the surgical population who are overweight, this is likely to place a considerable additional burden on the NHS. Strategies for mitigating this excess risk need to be found.

Lipid profile changes in patients undergoing bariatric surgery: a comparative study between sleeve gastrectomy and mini-gastric bypass

OBJECTIVE

To prospectively evaluate the effect of different types of bariatric surgery on lipid profile.

METHODS

Total cholesterol (TC), High-Density-Lipoprotein cholesterol (HDLc), Low-Density-Lipoprotein cholesterol (LDLc) and triglycerides (TG) levels were evaluated before surgery and at 3 different post-operative time-points (3, 6 and 12 months) in consecutive obese subjects undergoing mini-gastric bypass (MGB) or sleeve gastrectomy (SG).

RESULTS

At baseline, 74 MGB and 86 SG subjects were comparable for lipid profile and prevalence of hypercholesterolemia/hypertriglyceridemia. During the post-operative follow-up, both MGB and SG subjects showed significant changes in lipid profile. However, at 3 months, MGB patients showed higher changes in TC (β = 0.179, p = 0.022) and TG (β = 0.265, p = 0.001) than those undergoing SG. At 6-month post-operative follow-up, these differences were confirmed only for TC. After a 12-month follow-up, MGB and SG were entirely comparable for changes in lipid profile with the exception of HDLc, whose changes were higher in SG group (β = 0.130, p = 0.039). Overall, the probability to normalize lipid profile during the 12-month follow-up was similar in MGB and in SG patients (OR:1.24, 95%CI:0.41-3.76, p = 0.689).

CONCLUSION

Despites some differences at 3-6 post-operative months, during a 12-month follow-up, SG and MGB showed a similar efficacy in the improvement of lipid profile of obese patients.

Haemostatic and fibrinolytic changes in obese subjects undergoing bariatric surgery: the effect of different surgical procedures

BACKGROUND

Little is known about effects of different bariatric surgery procedures on haemostatic and fibrinolytic parameters.

MATERIAL AND METHODS

Consecutive obese subjects undergoing gastric bypass (GBP) or sleeve gastrectomy (SG) were enrolled. In all patients, levels of haemostatic factors (FII, FVII, FVIII, FIX, FX, vWF, fibrinogen), fibrinolytic variables (PAI-1, t-PA and D-dimer) and natural anticoagulants (AT, protein C and protein S) were evaluated before and 2 months after surgery.

RESULTS

A total of 77 GBP and 79 SG subjects completed the study. At baseline no difference in coagulation parameters was found between the two groups. After both GBP and SG, subjects showed significant changes in haemostatic and fibrinolytic variables and in natural anticoagulant levels. The Δ% changes in FVII, FVIII, FIX, vWF, fibrinogen, D-dimer, protein C and protein S levels were significantly higher in subjects who underwent GBP than in those who underwent SG. Multivariate analysis confirmed that GBP was a predictor of higher Δ% changes in FVII (β=0.268, p=0.010), protein C (β=0.274, p=0.003) and protein S (β=0.297, p<0.001), but not in all the other variables. Following coagulation factor reduction, 31 subjects (25.9% of GBP and 13.9% of SG; p=0.044) showed overt FVII deficiency; protein C deficiency was reported by 34 subjects (32.5% of GBP vs 11.4% of SG, p=0.033) and protein S deficiency by 39 (37.6% of GBP vs 12.6% of SG, p=0.009). Multivariate analyses showed that GBP was associated with an increased risk of deficiency of FVII (OR: 3.64; 95% CI: 1.73-7.64, p=0.001), protein C (OR: 4.319; 95% CI: 1.33-13.9, p=0.015) and protein S (OR: 5.50; 95% CI: 1.71-17.7, p=0.004).

DISCUSSION

GBP is associated with an increased risk of post-operative deficiency in some vitamin K-dependent coagulation factors. Whereas such deficiency is too weak to cause bleeding, it is significant enough to increase the risk of thrombosis.

Antibiotic prophylaxis in obese patients submitted to bariatric surgery. A systematic review

PURPOSE

To review the use of cefazolin in prophylaxis of surgical wound infection (SSI) in bariatric surgery (BS).

METHODS

A systematic review was performed from October to November, 2013 using the following databases: The Cochrane Library, Medline, LILACS, and EMBASE. The inclusion criteria were randomized clinical trials and observational studies that were evaluated by two independent reviewers.

RESULTS

Nine hundred and sixty one titles were recovered after preliminary analysis (title and abstract), seven studies remained for final analysis. There were three clinical trials (one with SSI, and two with antibiotic levels as the outcome), and four were observational studies (three cohorts and one case-control, all had SSI as the outcome). After administration of 1g or 2 g, levels of cefazolin in serum and tissue were suboptimal according to two studies. Results from observational studies indicated that different antibiotics were used for prophylaxis of SSI in BS and that use of other drugs may be associated with higher rates of SSI.

CONCLUSION

The use of cefazolin for surgical wound infection prophylaxis in bariatric surgery is recommended, however further studies are needed in order to refine parameters as initial dose, redose, moment of administration and lasting of prophylaxis.

Surgical site infection in spinal surgery: a comparative study between 2-octyl-cyanoacrylate and staples for wound closure

BACKGROUND

Surgical site infection (SSI) after spinal surgery is a devastating complication. Various methods of skin closure are used in spinal surgery, but the optimal skin-closure method remains unclear. A recent report recommended against the use of metal staples for skin closure in orthopedic surgery. 2-Octyl-cyanoacrylate (Dermabond; Ethicon, NJ, USA) has been widely applied for wound closure in various surgeries. In this cohort study, we assessed the rate of SSI in spinal surgery using metal staples and 2-octyl-cyanoacrylate for wound closure.

METHODS

This study enrolled 609 consecutive patients undergoing spinal surgery in our hospital. From April 2007 to March 2010 surgical wounds were closed with metal staples (group 1, n = 294). From April 2010 to February 2012 skin closure was performed using 2-octyl-cyanoacrylate (group 2, n = 315). We assessed the rate of SSI using these two different methods of wound closure. Prospective study of the time and cost evaluation of wound closure was performed between two groups.

RESULTS

Patients in the 2-octyl-cyanoacrylate group had more risk factors for SSI than those in the metal-staple group. Nonetheless, eight patients in the metal-staple group compared with none in the 2-octyl-cyanoacrylate group acquired SSIs (p < 0.01). The closure of the wound in length of 10 cm with 2-octyl-cyanoacrylate could save 28 s and $13.5.

CONCLUSIONS

This study reveals that in spinal surgery, wound closure using 2-octyl-cyanoacrylate was associated with a lower rate of SSI than wound closure with staples. Moreover, the use of 2-octyl-cyanoacrylate has a more time saving effect and cost-effectiveness than the use of staples in wound closure of 10 cm in length.

Factors affecting the risk surgical site infection and methods of reducing

According to estimates by the National Audit Office (NAO) hospital acquired infections (HAl), in particular surgical site infections (SSls), cost the NHS on average 3200 pounds per SSI and cause a mortality rate of at least five thousand patients a year (Leaper 2010). Despite practitioners' knowledge of safe working technique and control of infection, reported cases of nosocomial infections are still high, despite a reduction in-rate from 9% in 1993/4 to 8.2% in 2006 (Roberts & Cookson 2009).

Epidemiology and outcomes associated with surgical site infection following bariatric surgery

BACKGROUND

Surgical site infection (SSI) is a frequent problem complicating bariatric surgery. However, the potential risk factors, risk stratification, and outcomes of SSIs in this patient population remain poorly defined. The aim of this prospective case-control study was to characterize better the risk factors and to improve risk stratification for SSIs following bariatric surgery.

METHODS

Patients studied had SSI following Roux-en-Y gastric bypass surgery (RYGBS) between November 2006 and March 2009 at Harper University Hospital and were each matched with 3 controls based on type of operative procedure, surgeon, and year of surgery. Thirty-day outcomes included mortality, hospital readmissions, outpatient procedures, and emergency room visits. A scoring system (BULCS score) was compared with the National Nosocomial Infections Surveillance system risk index using logistic regression.

RESULTS

In multivariate analysis, duration of surgery (odds ratio [OR], 3.3; 95% confidence interval [CI]: 1.62-6.74), diagnosis of bipolar disorder (OR, 3.341; 95% CI: 1.0-12.27), use of prophylactic antibiotics other than cefazolin (OR, 4.2; 95% CI: 1.47-11.69), and sleep apnea (OR, 1.8; 95% CI: 1.05-2.97) were significantly associated with SSI. Patients with SSI were more likely to have return emergency visits (OR, 4.96; 95% CI: 2.9-8.48), readmission (OR, 6.53; 95% CI: 3.44-12.42), and outpatient procedures following surgery (OR, 4.75; 95% CI: 1.32-17.14) than were controls without SSI. The BULCS score was a stronger predictor of SSI than the National Nosocomial Infections Surveillance system (C-statistic, -0.62 vs 0.55, respectively).

CONCLUSION

SSI following bariatric surgery was associated with receipt of antibiotic prophylaxis other than cefazolin and comorbid conditions including sleep apnea and bipolar disorder. The BULCS score performed favorably as a predictor and risk adjuster for SSI following bariatric surgery. SSI was associated with increased health care resource utilization.

The importance of the gut microbiota after bariatric surgery

The gut microbiota is recognized to have an important role in energy storage and the subsequent development of obesity. To date, bariatric surgery (indicated for severe obesity) represents the only treatment that enables substantial and sustained weight loss. Bariatric surgery is also a good model to study not only the pathophysiology of obesity and its related diseases but also the mechanisms involved in their improvement after weight reduction. Scarce data from humans and animal models have demonstrated that gut microbiota composition is modified after Roux-en-Y gastric bypass (RYGB), suggesting that weight reduction could affect gut microbiota composition. However, weight loss might not be the only factor responsible for those modifications. Indeed, bariatric surgery not only improves hormonal and inflammatory status, but also induces numerous changes in the digestive tract that might account for the observed modifications of microbiota ecology. In future bariatric surgery studies in humans or mice, these major surgery-induced modifications will need to be taken into account when analyzing the link between gut microbiota composition, obesity, its complications and their improvement after bariatric surgery. This Review outlines the potential mechanisms by which the major changes in the digestive tract after bariatric surgery can affect the gut microbiota.